TM 10-4610-215-10TM 08580A-10/1Generator Set (Army). Instructions for operating the generator are contained in the applicablegenerator set manual (TM 5-6115-465-12 for NSN 6115-00-118-1240).b. Color Comparator Test Kit. Instructions to determine the pH values and chlorine residual in waterare contained in the color comparator test kit (para. 217, fig. 2-14). The Diethyl-P-Phenylene Diamine (DPD)tablets are not part of the test kit, but are included in Storage Box No. 3.c.TDS Meter (Portable). The TDS (total dissolved solids) meter is a calibrated meter that measureshow much electric current can flow through a sample of water. Pure water passes almost no current.(1) Description of the TDS meter:(a) Reads in ppm (parts per million) or in mg/l (milligrams per liter).(b) Has three scales: 0 to 5 x 10,0 to 5 x 100, and 0 to 5 x 1000.(c) Change scales with the range switch.Figure 2-77. Total Dissolved Solids (TDS) MeterCAUTIONAlways start with meter set on the 0 to 5 x 1000 scale. If you use a lower scalefirst, you may damage the meter.NOTEThe TDS meter is factory calibrated and suitable for use when treating fresh(lake, stream, pond, river) water. When treating seawater and brackish water, itis necessary to recalibrate the meter. If your meter has both 442 and NaClinternal standards stamped on the bottom panel, obtain a standard sodiumchloride (NaCl) solution (ArmySC-4610-97-CL-E16; MC  SL3-08580A)and refer to subpara. (3).(2) Recalibration instructions for meters with both internal standards (442 and NaCl) stampedon the bottom of the meter:2-83a.